JPS61165784A - Hologram - Google Patents

Abstract

PURPOSE:To decrease the thickness of a photosensitive material and to improve diffraction ratio by using a non-crosslinked polymer for a polymer and a carrier having >=1mum and <10mum thickness and forming the polymn. product of the crosslinked polymn. product having >=50% diffraction efficiency. CONSTITUTION:A photopolymerizable material contg. a multifunctional monomer is dispersed into the non-crosslinked polymer to be used as the carrier and the carrier is prepd. to >=1mum and <10mum thickness. The photopolymerizable monomer induces photopolymn. and the polymerization product crosslinked according to the interference pattern is formed in the carrier when such photosensitive material for hologram recording is exposed to the interference pattern by two-beam coherent radiation ray sources of an object wave and reference wave. The hologram is eventually recorded. The hologram having >=50% diffraction efficiency is obtd. when the photosensitive material is thereafter subjected to a solvent treatment. The resolving power, transmittance and sensitivity, etc. are thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to holograms, particularly volume phase holograms. After all, recording bodies that record interference fringes of light, ie, holograms, are expected to find wide application in the field of information processing, image display, and optical measurement.

(Prior art and its problems) Conventionally, photochromic materials, chalcogen glasses, thermoplastics, silver salts, photoresists, photopolymers, dichromate gelatin, ferroelectrics, and ferromagnetic materials have been used as sensitive materials for hologram recording. However, all of them have advantages and disadvantages, and at present there are very few that satisfy practical requirements. Particularly, except for silver salts, dichromate gelatin, and photopolymers, there is a disadvantage that they have no visible sensitivity and are mainly limited to use in the ultraviolet region.

Also, even with dichromate gelatin, which has visible sensitivity, you cannot use anything other than chromium salts.

Therefore, there is a restriction that the sensitive wavelength range is limited.

Silver salt is sufficient as a sensitive material for hologram recording in terms of sensitivity, but it suffers from a reduction in resolution and transmittance due to the particle nature of silver, and especially in light resistance after bleaching, it has the serious drawback of darkening. have.

In addition, in order to obtain high diffraction efficiency with photopolymers, the thickness of the sensitive material must be extremely thick, and the sensitizer used to obtain visible sensitivity may remain in the resulting product. Problems such as a decrease in transmittance and coloration cannot be avoided.

By the way, the types of holograms can be classified into amplitude type and phase type, and the theoretical maximum diffraction efficiency of the amplitude type is 7.2%. On the other hand, in the phase type hologram, the formula defined by Kogelnitsa is Q=(2π input d/no
A') (input is the wavelength of light, d is the thickness of the photosensitive layer, no is the average refractive index, and Δ is the period of interference fringes), when Q is 10 or more, it is a volume type, and when it is less than 10, it is a planar type. The type that can obtain high diffraction efficiency is the volume type hologram, which has a theoretical maximum diffraction efficiency of 100%.
%. When using a photopolymer for such a volume type phase hologram, the thickness of the sensitive material is several 10#.
Lm~several 100 gm is required. In addition, when using dichromate gelatin, the thickness of the sensitive material should be 10 pm or less (la μ
A volume phase hologram was obtained in (m).

Therefore, the present invention aims to eliminate various drawbacks seen in such conventional hologram recording materials, and further uses a sensitive material having a thickness of only a few μm, that is, a thickness of 14 m or more and less than 10 gm. (1) High diffraction efficiency, (2) 2.
Holograms with excellent features such as resolution of 000 lines/■ or more, (3) no coloration, (4) high transmittance, (5) wide sensitivity range covering ultraviolet and visible wavelength ranges, and (6) high sensitivity. The purpose is to provide.

(Disclosure of the Invention) To be more specific here, in the present invention, a polymer is used as a carrier, and a portion in which a polymer of a photopolymerizable monomer is mixed is formed in the carrier according to an interference pattern. In the volume type phase hologram, the above-mentioned drawbacks of the prior art are solved by making the above-mentioned polymer a non-crosslinked polymer, making the thickness of the carrier 1 μm or more and less than 1107t, and making the above-mentioned polymer a crosslinked polymer. Thus, the above-mentioned object of the present invention has been achieved.

Such holograms are produced by dispersing a photopolymerizable material containing a polyfunctional monomer in a non-crosslinked polymer serving as a carrier, and exposing a photosensitive material prepared to a thickness of several Bm to an interference pattern of radiation. a first step; a second step of bringing the light-sensitive material into contact with a first solvent that shows a difference in swelling or solubility depending on the interference pattern formed in the light-sensitive material; The hologram is obtained by a method for producing a hologram, which comprises a third step of bringing the sensitive material into contact with a second solvent that is miscible with the material and has poor moisturizing or dissolving effects on the sensitive material.

The term photopolymerizable substance used in the present invention is (
I) Compounds (especially monomers) having ethylenically unsaturated bonds
, (II) a polymerization initiator, and (III) a photosensitizer.1 For example, it can be used in all existing photopolymerization systems such as dye-sensitized polymerization, redox polymerization, and C-T complex polymerization. Can be applied. Regarding these photopolymerizable substances, see the paper by G. Oster, Chew Re
v 88125 (11388) etc.

Incidentally, specific examples (not limited to these) of various materials used in the present invention are as follows.

(■), as a compound having an ethylenically unsaturated bond,
Vinyl ketones such as acetoxymethyl vinyl ketone, phenyl vinyl ketone, divinyl ketone, maleimide,
Maleimides such as N-ethylmaleimide and N-3-7 setoxyprobylmaleimide; acrylamides such as acrylamide, N-methylolacrylamide, and N,N''-methylenebisacrylamide; methyl acrylate, triethylene glycol dimethacrylate, diethylene glycol Acrylic esters such as diacrylate and methyl methacrylate; Acrylic acid salts such as barium acrylate, lead acrylate, and calcium acrylate; N
-Vinylcarbazole and the like.

These monomers are preferably used as a monomer mixture containing 5 to 50 mol% of polyfunctional monomers, and the polymer formed from these monomer mixtures is made into a crosslinked polymer, With such a configuration, even though the carrier is extremely thin, it is possible to produce an excellent high diffraction index etc. by the solvent treatment described below. If the amount of polyfunctional monomer is too small, there will be little difference in physical properties such as swelling properties in solvents between the formed polymer and the non-crosslinked polymer as a carrier, and if it is too large, swelling of the photopolymerized product in solvents will be small. This is not desirable because the performance becomes too low.

(rr) Sensitizers include ketones such as benzophenone, diacetyl, and chloroacetone; peroxides such as t-butyl hydroperoxide, benzoyl peroxide, and di-butyl peroxide; diphenyl disulfide, dibenzothiazole disulfide, Sulfur compounds such as tetramethylthiuram monosulfide; azo compounds such as azoxystyrene and azobisisobutyronitrile; halogen compounds such as iodoform, carbon tetrachloride, and bromotrichloromethane; manganese carbonyl,
Examples include metal carbonyls such as rhenium carbonyl; metal salts such as iron (■) ammonium citrate, acopentaammine cobalt (m) nitrate, and uranyl nitrate; pigments such as riboflavin, methylene blue, and rose bengal.

In the present invention, in addition to the above-mentioned photopolymerizable substance, various polymers serving as carriers are used as essential elements constituting the sensitive material for hologram recording. For example, natural polymers such as gelatin, casein, and starch; semi-synthetic polymers such as natural rubber plastics such as chlorinated rubber and cyclized rubber;
Polyimbutylene, polystyrene, terpene resin, polyacrylic acid, polyacrylic ester, polymethacrylic ester, polyacrylonitrile, polyacrylamide, polyvinyl acetate, polyvinyl alcohol, polyvinylpyrrolidone, polyacetal resin, polyvinylpyridine, polyvinyl carta Polymerizable synthetic polymers such as sol, polybutadiene, polystyrene-butadiene, butyl rubber, polyoxymethylene, polyethyleneimine, polyethyleneimine hydrochloride, poly(2-acryphleoxyethyldimethylsulfonium chloride), amino resins, toluene resins, Examples include condensation polymerization type synthetic polymers such as alkyd resins, unsaturated polyester resins, allyl resins, polyamide resins, polyether resins, furan resins, thiocol rubbers, and addition polymerization type resins such as polyurethane. Such a polymer is selected and used because it can disperse the photopolymerizable substance well and has an appropriate action on the solvent used in the hologram amplification process in the present invention, which will be described in detail later. Preferably.

The thickness of the carrier formed from such a non-crosslinked polymer is
In the present invention, several Bm, that is, 10 pL or more than 1 Bm
It is desirable to have a thickness of m without grooves, that is, 1. Due to the synergistic effect with other structures of the present invention (for example, the formed polymer is a crosslinked polymer), even such a thin support can have high diffraction. The above-mentioned effects can be achieved by
When the thickness of these carriers is 1OILm or more, various effects such as no coloration, high transmittance, and high sensitivity are reduced.

The hologram recording sensitive material used in the present invention is prepared approximately as follows. For example, one method is:
The above-mentioned polymer, photopolymerizable substance, and, if necessary, a solvent are added to obtain a dispersion mixture.

Alternatively, it can be applied as a dissolved solution to a support such as glass or resin film using a known method such as a spinner method or a dipping method, or if the polymer to be used as a support can be formed into a film by itself. , to form a film without using a support. Another method is to provide only the pentapolymer as a coating film on the support, or
After forming itself into a film, it can also be made into a sensitive material by impregnating it with a solution of a photopolymerizable substance by a method such as a dipping method.

The latter method has various advantages over the former method. For example, a darkroom operation step is not necessary during application, which is preferable in terms of shelf life. Furthermore, the biggest advantage is that the selection range of polymers that can be used as a carrier, which is an essential component of the hologram sensitive material according to the present invention, is increased. That is, according to this method, when there is no solvent to dissolve both the polymer and the photopolymerizable substance, or even if there is a solvent that dissolves both, it will not dissolve unless a large amount is used, so even if applied to the support, it will not dissolve. Even when it is difficult to obtain the required thickness of the photosensitive material, the polymer is dissolved in a solvent and applied to the support, and the coated material is infiltrated into a photopolymerizable substance by immersion, etc. The photopolymerizable substance is dissolved or diluted. This problem can be solved by using different types of solvents. Furthermore, according to this method, if the polymer coated on the support has weak film properties as it is, or if it comes into contact with a solvent when permeating a photopolymerizable substance or during the process of creating a hologram, If the hologram recording is unfavorably affected by peeling or dissolution of the sensitive material film, the polymer coated on the support should be impregnated with a photopolymerizable substance and then subjected to physical treatment, such as heat drying, before sensitization. For example, protein polymers such as gelatin are treated with formalin, light bread, etc.

In this way, the polymerization rate, pre-polymerization, etc. on the photopolymerizable substance are formed in a state where there is no influence at all, or even if there is an influence, it is minimal, and factors that have an undesirable influence on hologram recording are eliminated. You can create a car that does When forming various films as described above, it is desirable that the thickness of the obtained carrier is several pm, that is, 1) tm or more and less than 10 ILm, and at such a thickness, the photopolymerizable substance is uniformly deposited into the carrier. Penetration is achieved, and the above-mentioned properties such as non-coloring property and high sensitivity are further improved.

When the hologram recording sensitive material prepared by the above method is exposed to an interference pattern produced by two bundles of coherent radiation sources, an object wave and a reference wave, the photopolymerizable monomer in the polymer carrier (a monomer mixture compound containing a polyfunctional monomer having two or more ethylenically unsaturated bonds) undergoes photopolymerization, and a crosslinked polymer is formed in the carrier according to the interference pattern, resulting in the formation of a hologram. is recorded.

Such a process is carried out using an optical system as shown in the first figure. That is, coherent light B emitted from a radiation source 1, such as a laser oscillator or a mercury lamp, is split into two by a beam splitter 2, each beam Bl and B2 is expanded by optical lens systems 3 and 3', and parallel light is generated. The photosensitive material 4 is exposed to the interference pattern. Incidentally, 5 is a reflecting mirror, and 6
is a light-absorbing plate coated with anti-reflection paint.

Conventionally, in a hologram production method using a photopolymer, a light-fixing process is performed after exposing a sensitive material to an interference pattern. One of them is the 1uPont method, in which a photopolymerized material is dispersed in a polymeric binder, exposed to an interference pattern, a diffusion time is set, and then the entire surface is irradiated with light, and the unpolymerized portion is also causes polymerization to obtain a hologram image, and the other one is Hu
This is the GHS method, in which an aqueous solution of the photopolymerized product is sealed in a spacer, exposed to an interference pattern, and then the entire surface is irradiated with UV light to inactivate the sensitizing dye and prevent further polymerization of the unpolymerized dye. A hologram image is obtained by processing the image so that it does not occur. However, in both cases, there is a proportional relationship between the thickness of the photosensitive material and the diffraction efficiency, and in order to obtain high diffraction efficiency, the thickness of the photosensitive material must be made extremely thick. By the way, DuPont
With photopolymer, diffraction efficiency is 80 at photosensitive material thickness of 50 pm.
%, Hugh s photopolymer has a sensitive material thickness of 25p.
It is known that the diffraction efficiency is 30% at m.

A major feature of the present invention is that the sensitive material is subjected to a solvent treatment step after being exposed to the interference pattern. By carrying out such a step, the diffraction efficiency of the hologram is amplified, and in general, a diffraction efficiency of 50% or more, and in many cases about 80%, can be obtained with a photosensitive material thickness of 3 ILm.

The reason why a hologram image with high diffraction efficiency can be obtained without depending on the thickness of the photosensitive material is not yet fully understood, but it is believed that the change in internal refractive index is increased by solvent treatment. seems certain. By treating the photosensitive material with a solvent, unpolymerized monomers can be removed, and the sensitizer, which is a coloring component, can also be removed, making it possible to obtain extremely clear hologram images. The thinner it is, the more effective it is.

In such solvent treatment, if a solvent that dissolves the unpolymerized photopolymerizable substance well and has little solubility for the polymer is selected and used, it is possible to fix the hologram and remove the colored components, but the hologram is There is almost no effect of increasing diffraction efficiency. However, it is necessary to have sufficient solubility in unpolymerized photopolymerizable substances, as well as polymers of photopolymerizable monomers polymerized according to the interference pattern, and polymers or hologram sensitive materials as carriers. , a first solvent treatment is performed on areas where photopolymerization has occurred and areas where photopolymerization has not occurred according to the interference pattern using solvents having different effects such as solubility or swelling properties, respectively; Next, another solvent that is miscible with the above solvent and has little or no activity on the polymer and photopolymerizable substance that are components of the hologram sensitive material is used. By performing the second process, the hologram can be fixed and colorless, and the diffraction efficiency can be dramatically improved.

In other words, such a dramatic improvement in diffraction efficiency can be achieved by selecting a non-crosslinked polymer as the polymer constituting the carrier and using a monomer having two or more ethylenically unsaturated bonds as a photopolymerizable monomer. By using a monomer mixture containing a polymer, the photopolymerized product is crosslinked to some extent, and a difference is created between the carrier polymer and the photopolymerized product in solubility in the first solvent, particularly in swelling property, and then A dramatic improvement in diffraction efficiency was achieved by shrinking the llIIIll portion with the second solvent. On the other hand, when no crosslinking occurs in the photopolymerized product, the first bond between the carrier and the photopolymerized product
The improvement in diffraction efficiency cannot necessarily be said to be sufficient because the difference in activity with respect to solvents is not significant.

The hologram of the present invention will be further described in detail by giving specific examples.

A hydrophilic polymer such as gelatin, gum arabic, or polyvinyl alcohol is used as a polymer to serve as a carrier, and a polyfunctional water-soluble polymer such as N,N'-methylenebisacrylamide is used as a photopolymerizable monomer. Taking as an example a photosensitive material obtained using a water-soluble monomer such as acrylamide or barium acrylate, the photosensitive material 204 is formed into an interference pattern L as shown in FIG. 2(a). After exposure to water, the sensitive material 204 is treated with a solvent such as methanol, ethanol, isopropanol, or THF that dissolves water-soluble monomers well and hardly dissolves polymers of monomers or polymers used as carriers. (Specifically, for example, by immersion.) Then, as shown in FIG. 2(b), only the photopolymerizable material in the portion of the sensitive material zo4y that was not exposed to the interference pattern is removed, and as shown in FIG. 2(C). As shown in FIG. 2, a portion where a polymer of a photopolymerizable monomer is mixed is formed in the polymer serving as a carrier according to the interference pattern, and a hologram is completed. In such a hologram manufacturing method, the refractive index (nl) inherent to the polymer that should be the refractive index change of the obtained hologram,
Average refractive index of polymer of carrier polymer and photopolymerizable monomer (
n2), [In addition, the refractive index of the polymer of the photopolymerizable monomer is n3
] The ratio of the amount of the polymer to the polymer of the photopolymerizable monomer is a
:b, n2 = ((ant +bn3) /
(a + b) ), that is, (nl-n2
), but since the refractive index change in this case is proportional to the thickness of the photosensitive material, it is difficult to obtain high diffraction efficiency when the photosensitive material is several gm thick.

However, first, the sensitive material is treated with a first solvent, such as water or a water-alcohol mixed solvent, which has a certain degree of solubility, especially swelling ability, even for the above-mentioned polymer or polymer. When the second treatment is performed with another solvent such as ethanol, isopropanol, or TI(F) that is miscible with the first solvent and hardly dissolves the polymer, the first solvent The carrier and the photopolymerized product were in different swelling states, and since the solvent was replaced by the second solvent and the carrier and the photopolymerized product were in a different 1N wet state, internal image distortion according to the interference pattern occurred. 204x' and zo47 shown in FIG. 2(C)
The change in refractive index between
This is a very large difference, and a hologram with even higher diffraction efficiency can be obtained compared to the method described above. On the other hand, when the carrier polymer and the photopolymerized product are in a state where there is no difference with respect to the first solvent, that is, the photopolymerized product is also a non-crosslinked polymer, the swelling due to the first solvent and the second solvent Since both contractions occur in parallel, internal strain is less likely to occur.

Similarly, when using a hydrophobic polymer such as polyvinylcarbazole, polystyrene, polyvinylpyridine, etc. as a polymer to be a carrier, a solvent such as toluene, xylene, or chloroform is used as the first solvent,
By treating with a solvent such as alcohol or n-hexane as the second solvent and then drying, a hologram with high diffraction efficiency and increased internal refractive index change can be obtained as before.

That is, in the present invention, the factors that determine the magnitude of the diffraction efficiency of a hologram are mainly the difference in the solvent properties of the carrier polymer and the photopolymerized product, particularly the swelling properties, and the solvent treatment process.

Therefore, in the hologram created in the exposure process, the difference in wWR properties of the carrier polymer and the photopolymerized material forming the hologram with respect to the solvent is further amplified into a change in the refractive index in the solvent treatment process, and as a result, the thickness of the carrier increases. This results in a hologram with an unexpectedly high diffraction efficiency.

As described above, in the present invention, when forming a hologram with a hologram sensitizer using a polymer containing a photopolymerizable monomer as a carrier, a general non-crosslinked polymer is used as a carrier polymer, and By using a photopolymerizable monomer containing an appropriate amount of a polyfunctional monomer and giving the photopolymerized product a crosslinked structure, a difference is created in the swelling properties of the two in the first solvent treatment, and further In the second solvent treatment, the difference in physical properties between the two is further expanded, and this difference is manifested in a change in the refractive index, making it possible to achieve an unimaginably high diffraction efficiency even with a thin sensitizer of only a few gm. At the same time, by using a very thin sensitizer, we have achieved various effects that cannot be achieved with conventional relatively thick sensitizers, such as resolution of over 2,000 lines/■■, high transmittance, and high sensitivity. This was achieved.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Acrylamide 100gN, N'
-Methylenebisacrylamide 110g Triethanolamine 5g Methylene blue
0.01g water
100mJL Ig of the photosensitive solution having the above composition was mixed with 7g of a 20% gelatin aqueous solution, heated to 45°C, and plated onto a glass plate with a spinner to a thickness of 3#L.
After applying the film to M, it was naturally dried to obtain a photosensitive material for hologram deployment. Using an optical system similar to that shown in Figure 1, hologram recording was performed by applying exposure energy of 50 sj/ctn' to the sensitive material using a He-Me laser with a wavelength of 63:3+m. Wash with water and further 30% at 20℃
The sample was immersed in mixed water isoproper tool for 30 seconds, further immersed in isoproper tool at 20° C. for 2 minutes, and then immediately dried with hot air using a hair dryer to complete the hologram.

The diffraction efficiency of the obtained hologram (volume phase hologram) was 79%, and the spatial frequency was 2,000 lines/■ layer.

Example 2 Acrylamide 100gN, N'
-Methylenebisacrylamide 10g Triethanolamine 5g Methylene Blue
0.01g water
Gelatin having a thickness of 5 ILm, which had been hardened in advance on a glass plate, was immersed in a photosensitive solution having the above composition for 5 minutes and air-dried for 2 hours to obtain a photosensitive material.

He-Me laser 63 using the same optical system as shown in the first figure.
Hologram recording was performed by applying exposure energy of 50*j/crn' to the sensitive material at a wavelength of 3n■. This was washed with water, then immersed in isopropanol containing 30% water for 30 seconds, further immersed in isopropanol for 2 minutes, and then immediately dried with hot air using a dryer to obtain a hologram of wood/wooden soda with a spatial frequency of 2,000.

The diffraction efficiency of the holograms obtained by changing the water washing conditions as shown in the table below was as shown in the table below.

Further, the diffraction efficiency of the holograms obtained by changing the exposure energy (however, the water washing conditions were constant; 30° C. for 2 minutes) was as shown in the table below.

Examples 3 to 6 A coating film of a hydrophilic polymer (1) with a thickness of 3 ILm pre-hardened on a glass plate was exposed to a photosensitive material containing a sulfuric acid having a lignophilic group. After immersing it in solution (2) for 5 minutes and drying it naturally for 2 hours to obtain a sensitive material, it was exposed to laser light (3) using the same optical system as shown in Figure 1 to perform hologram recording. Thereafter, it was washed with water (4), then immersed in 30% water-containing isoproper tool for 30 seconds, further immersed in inproper tool for 2 minutes, and immediately dried with hot air using a dryer to complete the hologram (5).

Specific examples of the above items (1) to (5) are as follows.

"Shidodo 1" (1) Methyl cellulose (2) Barium acrylate 100gN, N
'-Methylenebisacrylamide og Methylene blue 0.01gP-Toluenesulfinic acid salt f0.3g Water
300m sentence (3) He-N1! L/-
laser 633n-130mj/cm' (4) 30°C, 2 minutes (5) Diffraction efficiency 73%, spatial frequency 2, 000 wood ZI
1 layer blue filter (1) Polyvinyl alcohol (2) Acrylamide 100gN, N
'-Methylenebisacrylamide 0g Triethanolamine 5g Iron(III) ammonium citrate 5g -t-Butyl hydroperoxide 1g Water
300m sentence (3) Ar laser 451nm
, 50+j/cm' (4) 60°C, 5 minutes (5) Diffraction efficiency 53%, spatial frequency 2,800 Wood/Soaking 1'' (1) Gum arabic (2) N-methylol acrylamide 100 g N, N
'-Methylenebisacrylamide 0g Triethanolamine 5g Acridine Orange 0.01g Water
300m sentence (3) Ar laser 488
ns, 80sj/Cn'l' (4) 45°C, 2 minutes (5) Diffraction efficiency 75%, spatial frequency 2, 600 lines/m
(1) Albumin (2) N-methylolacrylamide 100gN, N
'-Methylenebisacrylamide 0g Riboflavin 0.01g (4) 30℃
, 3 minutes (5) Diffraction efficiency 81%, spatial frequency 2, 900 lines/■
Layer Example 7 Acrylamide 9g N-Methylacrylamide IgN,N'-methylenebisacrylamide 1g Methylene Blue
0.001g triethanolamine
0.5g polyvinyl butyral 30
g Ethanol 100mJ1 Spread the photosensitive solution of the above composition onto a glass plate with a spinner to a thickness of 8IL.
A photosensitive material was obtained by coating the film on a substrate and drying it naturally. Holographic recording was performed on the obtained sensitive material by applying an exposure energy of 50 mj/crn' with a He-Me laser having a wavelength of 633 ns using an optical system similar to that shown in FIG. 50 pieces of that sensitive material
% methanol aqueous solution for 10 minutes at room temperature,
It was immersed in an isopropanol:toluene (1:1 mixture) solvent at 40° C. for 10 seconds. Furthermore, it was washed with n-hexane for 30 seconds and immediately dried with hot air to complete the hologram. The diffraction efficiency of the obtained hologram was 61%, and the spatial frequency was 2.
000 pieces/■■.

Example 8 Acrylamide 9g N-Methylacrylamide IgN, N'-methylenebisacrylamide 1g Methylene Blue
0.001g triethanolamine
0.5g? -vinylpyridine-2-methyl-5
-Vinylpyridine copolymer 25gT
A photosensitive solution containing 70 rnl of HF having the above composition was applied to a thickness of 2 m on a glass plate using a spinner, and after air drying, a photosensitive material was obtained.

Using the same optical system as shown in the first figure, the obtained sensitive material was He-
Ne laser - 100 mj/ClT at a wavelength of 633 nm
Holographic recording was performed by applying an exposure energy of 1". Next, the sample was immersed in an 80% ethanol aqueous solution for 10 minutes at room temperature, and then immersed in a carbon tetrachloride:THF (l:2 mixture) solvent at 40°C for 30 seconds. A hologram was obtained by immersing it in carbon tetrachloride for 1 minute and drying it with hot air.

The diffraction efficiency of the obtained hologram was 73%, and the spatial frequency was 2.
．． 000 bottles/meal.

Example 9 N-vinylcarbazole 10g ethylene glycol diacrylate 5g acrylic resin
35gNaAu Cu42H200, 1
g Acetone Ion A photosensitive solution having the above composition was applied to a thickness of 3 ILm on a glass plate using a spinner, and air-dried to obtain a photosensitive material.

The obtained sensitive material was subjected to hologram recording by applying an exposure energy of 200 mj/cm'' with an Ar laser at a wavelength of 488 nm using an optical system similar to that shown in the first figure.Next, after immersing it in ethanol for 10 minutes at room temperature, It was immersed in isopropyl ether for 2 minutes at 40°C.It was then immersed in xylene for 1 minute at room temperature.
After soaking for a minute, the hologram was completed by air drying.

The diffraction efficiency of the obtained hologram was 65%, and the spatial frequency was 2,600 lines/7 layers 1.

Example 1O Ethylene glycol diacrylate 5g Methyl methacrylate 5g Benzoin
0.05g polystyrene
40gTHF 10
0 ml of a photosensitive liquid having the above composition was applied to a glass plate to a thickness of 5 #Lm using a spinner, and air-dried to obtain a photosensitive material.

Using the same optical system as shown in the first diagram, the obtained photosensitive material was coated with Kr.
Hologram recording was performed by heating the sensitive material to 50°C using a laser with a wavelength of 351 ns and applying an exposure energy of 300 mj/cm'.Next, it was immersed in isopropanol (at room temperature) for 5 minutes, and then immersed in chloroform at 30°C. : Immersed in isopropyl ether (3:l mixture) solvent for 30 seconds.

Finally, it was immersed in n-hexane for 1 minute at room temperature, and then air-dried to obtain a hologram. The diffraction efficiency of the obtained hologram was 67%, and the spatial frequency was 3,000 lines/layer.

As described in detail above, according to the present invention, even if the thickness of the sensitive material is made sufficiently thin, it is possible to obtain a volume type phase hologram that has a high diffraction index and is extremely clear.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing an example of an optical system used in the process of the hologram manufacturing method of the present invention, and FIG.
), (b), and (c) are schematic diagrams for explaining changes in the photosensitive material during the hologram manufacturing process of the present invention. 4.204...Sensitive material for hologram recording Figure 1 Figure 2

Claims (4)

[Claims] (1) In a volume type phase hologram in which a polymer is used as a carrier and a portion in which a polymer of a photopolymerizable monomer is mixed according to an interference pattern is formed in the carrier, the polymer is a non-crosslinked polymer. A hologram characterized in that the carrier has a thickness of 1 μm or more and less than 10 μm, the polymer is a crosslinked polymer, and the diffraction efficiency is 50% or more. (2) The hologram according to claim (1), wherein the polymer is a hydrophilic polymer. (3) The hologram according to claim (1), wherein the polymer is a hydrophobic polymer. (4) The photopolymerizable monomer is a polyfunctional monomer having two or more ethylenically unsaturated bonds.
) The hologram described in section.